Regardless of where or how an
accident involving radiation happens, three types of radiation-induced injury can occur:
external irradiation, contamination with radioactive materials, and incorporation of
radioactive material into body cells, tissues, or organs.

External irradiation occurs when all or part of the
body is exposed to penetrating radiation from an external source. During exposure this
radiation can be absorbed by the body or it can pass completely through. A similar thing
occurs during an ordinary chest x-ray. Following external exposure, an individual is not
radioactive and can be treated like any other patient. (Refer to the sections on
assessment and treatment in Hospital Emergency Care of the
Radiation Accident Patient.)

The second type of radiation injury involves contamination
with radioactive materials. Contamination means that radioactive materials in the form of
gases, liquids, or solids are released into the environment and contaminate people
externally, internally, or both. An external surface of the body, such as the skin, can
become contaminated, and if radioactive materials get inside the body through the lungs,
gut, or wounds, the contaminant can become deposited internally. Refer to Managing Emergencies Involving Radiation for additional information.

The third type of radiation injury that can occur is incorporation
of radioactive material. Incorporation refers to the uptake of radioactive materials by
body cells, tissues, and target organs such as bone, liver, thyroid, or kidney. In
general, radioactive materials are distributed throughout the body based upon their
chemical properties. Incorporation cannot occur unless contamination has occurred. (Refer
to the section on assessment and treatment of the contaminated patient in Hospital Emergency Care of the Radiation Accident Patient.)